Buildresult: linus/arm64-allmodconfig/arm64-gcc8 built on Oct 16 2019, 05:23

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Status:	OK
Date/Time:	Oct 16 2019, 05:23
Duration:	0:29:04.932225
Builder:	blade4b
Revision:	sparc64: disable fast-GUP due to unexplained oopses (`8e0d0ad206f08506c893326ca7c9c3d9cc042cef)`
Target:	linus/arm64-allmodconfig/arm64-gcc8
Branch:	linus
Compiler:	arm64-gcc8 (aarch64-linux-gcc (GCC) 8.1.0 / GNU ld (GNU Binutils) 2.30)
Config:	allmodconfig (download)
Log:	Download original No warnings found in log. Full Log # git rev-parse -q --verify 8e0d0ad206f08506c893326ca7c9c3d9cc042cef^{commit} 8e0d0ad206f08506c893326ca7c9c3d9cc042cef already have revision, skipping fetch # git checkout -q -f -B kisskb 8e0d0ad206f08506c893326ca7c9c3d9cc042cef # git clean -qxdf # < git log -1 # commit 8e0d0ad206f08506c893326ca7c9c3d9cc042cef # Author: Linus Torvalds <torvalds@linux-foundation.org> # Date: Tue Oct 15 09:56:36 2019 -0700 # # sparc64: disable fast-GUP due to unexplained oopses # # HAVE_FAST_GUP enables the lockless quick page table walker for simple # cases, and is a nice optimization for some random loads that can then # use get_user_pages_fast() rather than the more careful page walker. # # However, for some unexplained reason, it seems to be subtly broken on # sparc64. The breakage is only with some compiler versions and some # hardware, and nobody seems to have figured out what triggers it, # although there's a simple reprodicer for the problem when it does # trigger. # # The problem was introduced with the conversion to the generic GUP code # in commit 7b9afb86b632 ("sparc64: use the generic get_user_pages_fast # code"), but nothing looks obviously wrong in that conversion. It may be # a compiler bug that just hits us with the code reorganization. Or it # may be something very specific to sparc64. # # This disables HAVE_FAST_GUP entirely. That makes things like futexes a # bit slower, but at least they work. If we can figure out the trigger, # that would be lovely, but it's been three months already.. # # Link: https://lore.kernel.org/lkml/20190717215956.GA30369@altlinux.org/ # Fixes: 7b9afb86b632 ("sparc64: use the generic get_user_pages_fast code") # Reported-by: Dmitry V Levin <ldv@altlinux.org> # Reported-by: Anatoly Pugachev <matorola@gmail.com> # Requested-by: Meelis Roos <mroos@linux.ee> # Suggested-by: Christoph Hellwig <hch@infradead.org> # Cc: David Miller <davem@davemloft.net> # Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> # < /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/aarch64-linux/bin/aarch64-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/aarch64-linux/bin/aarch64-linux-ld --version # < git log --format=%s --max-count=1 8e0d0ad206f08506c893326ca7c9c3d9cc042cef # < make -s -j 24 ARCH=arm64 O=/kisskb/build/linus_arm64-allmodconfig_arm64-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/aarch64-linux/bin/aarch64-linux- allmodconfig # make -s -j 24 ARCH=arm64 O=/kisskb/build/linus_arm64-allmodconfig_arm64-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/aarch64-linux/bin/aarch64-linux- Completed OK # rm -rf /kisskb/build/linus_arm64-allmodconfig_arm64-gcc8 # Build took: 0:29:04.932225

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